Lethal Factor
Lethal Factor - Related Videos
11:35
Quantifying Embryonic Lethality Rate in Caenorhabditis elegans
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2026
This protocol provides a simple, low-cost procedure to quantify the rate of embryonic lethality in Caenorhabditis elegans. It enables straightforward detection of embryonic abnormalities across populations without specialized equipment or worm-picking expertise. The protocol can be used to quantify the effects of genetic mutations, RNA interference-mediated gene knockdowns, and diet.
02:41
Lethal Alleles
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2021
Agouti: A Lethal Allele Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
09:09
Lethality Bioassay Using Artemia salina L.
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Cited by 19 •
2022
This work aims to evaluate and review the Artemia salina lethality bioassay procedure, also identified as brine shrimp lethality assay. This simple and cheap method gives information about the general toxicity (considered as a preliminary toxicity evaluation) of samples, namely, natural products.
08:39
Shifting Zebrafish Lethal Skeletal Mutant Penetrance by Progeny Testing
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Cited by 6 •
2017
The goal of this protocol is to alter the penetrance of lethal skeletal mutant phenotypes in zebrafish by selective breeding. Lethal mutants cannot be grown to adulthood and bred themselves, therefore this protocol describes a method for tracking and selecting penetrance through multiple generations by progeny testing.
14:40
Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana
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Cited by 34 •
2012
This study concerns the development and standardization of a valuable methodological protocol to determine long-term (14 days) lethal toxicity exerted by chemical substances, industrial wastewater or sewage and liquid environmental samples on the saltwater crustacean, Artemia franciscana.
FAQs
Zinc-dependent catalysis enables lethal factor to act as a protease rather than merely bind a host target. Once delivered into a host cell through protective-antigen-mediated entry, it cleaves mitogen-activated protein kinase kinases, or MAPKKs. This molecular cut interrupts signaling networks that coordinate immune responses, inflammation, and cell survival, linking enzymatic activity to anthrax toxin’s pathogenic effects.
Protective antigen functions as the entry-enabling component for lethal factor. Without this step, the protease cannot reach the host-cell environment where its relevant substrates are located, based on the described toxin mechanism. This division of labor illustrates why anthrax toxin must be considered as a three-protein system: lethal factor supplies enzymatic activity, while protective antigen enables access.
MAPKKs participate in signaling pathways that regulate immune responses, inflammation, and cell survival. Cleaving these kinases therefore disrupts coordinated cellular communication rather than affecting an isolated reaction. The resulting signaling interference helps explain how lethal factor contributes to tissue damage and disease progression, and why substrate recognition is central to understanding toxin-mediated pathology.
Researchers examine lethal factor’s structure and how it recognizes its substrates to connect molecular features with protease activity. This work can clarify which interactions support MAPKK cleavage and identify properties that may be useful for designing diagnostic tools or toxin-neutralizing therapies. It also provides a mechanistic basis for evaluating strategies intended to counter anthrax infections.
Because lethal factor is a central component of anthrax toxin activity, its study supports several applied goals: developing diagnostic tools, creating toxin-neutralizing therapies, and informing strategies to counter anthrax infections. These applications arise from understanding its structure, substrate recognition, and effects on host signaling. The same knowledge connects basic toxin biology with infectious-disease intervention.
Lethal factor provides a focused system for examining how a bacterial virulence system produces host damage through a defined molecular mechanism. In microbiology, it helps frame Bacillus anthracis toxin function; in infectious disease research, it relates toxin action to disease progression; and in toxin biology, it links protease structure and substrate recognition to cellular outcomes.